On those days, Springer's elegant solar home in Winters produces more power than it uses, giving him independence from the power grid and freedom from an electricity bill.

"And it makes for a very comfortable home," Springer said.

In addition to photovoltaic panels on his roof, Springer's home contains many high-tech and low-tech energy-saving devices. Some are as simple as awnings over his windows. Others include new technologies that draw cool breezes into the home during summer nights or that circulate cool water beneath his tile floors.

Today, Springer's home is one of thousands in the nation that will be opened to the public as part of the National Solar Tour Day, sponsored by the American Solar Energy Society. Yolo County, which will feature 12 homes, is the only county in the Sacramento region participating in this year's event, although some Sacramento County homes have been featured in the past. Nine other counties in Northern California also will open 90 homes for the tours.

Springer said he agreed to open his home to make a point. "I'd like to share with other people that (solar power is) possible and that it's a heck of a better alternative than building power plants," he said.

Springer is a co-founder of Davis Energy Group, a consulting firm that specializes in zero-energy homes.

In Yolo County, more than 220 solar electric systems  or photovoltaic systems  operate in homes and businesses, according to data from the California Energy Commission. About 200 of those systems are installed in Davis homes.

All told, PV systems in Yolo produce roughly 1.4 million kilowatt hours of energy a year. It is estimated that a typical California family of four consumes 534 kilowatts in an average month.

Organizers of today's tour say they want the public to know that harnessing the sun's power is possible, affordable and in some cases quite simple. Smart insulation  or securing of the "thermal envelope" of a home  also can dramatically save energy.

"It also benefits society in general," said Julie Haney, an architect who specializes in solar power and energy-efficient construction. "It's cleaner and puts less demand on the (power) grid."

Haney designed Springer's home, starting from the simple solar-friendly concept of orienting the home for southern exposure to the sun. The sun-baked windows also are covered with awnings to block the exposure when needed.

Liz Merry, an organizer of the Yolo tour, said she and other advocates of green energy such as solar power hope to get the word out to builders in the region that orienting neighborhood streets on east-to-west configurations allows homes to be oriented north to south, which provides homes more southern sun exposure.

Other energy-saving features in Springer's home include added insulation in the walls along with tile floors and granite countertops that contribute to thermal mass.

Springer developed the sophisticated "NightBreeze" summer cooling system. The system ventilates the house at night with outdoor air, which cools off the thermal mass in the home, thereby keeping it cooler during the next day. If the house does not cool to 72 degrees Fahrenheit by 4 a.m., an air conditioner will chill water that runs through the floor and shuts off by 8 a.m. The floor stores the cooled water, keeping the house comfortable during the day.

Springer estimates he spent about $20,000 on the home's energy-saving upgrades. He also received some rebates and tax breaks for the systems.

The energy bills on his 2,400-square-foot home this summer were about $4.50 a month, down from about $125 for the previous summer bills before the new energy systems were installed.

For more information People wishing to participate in today's Yolo County's solar tour must collect maps and pay a fee at the Davis Farmer's Market before noon at Third and B streets in Davis. The tours run from 10 a.m. to 4 p.m. Cost for the tour is $15 for a carload of up to five participants. For more information, visit www.norcalsolar.org.

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